In order to write the dissertation, you must complete extensive, detailed research, and there are different types of research for different types of studies—involving very different methodology.

“The method of research is informed by the research question,” says Garvey House, PhD, associate director of research and residencies for Capella University’s School of Business and Technology. “The problem that’s being addressed usually involves either a gap or a controversy in the literature.” Once the research problem has been identified, the student can employ the methodology best suited for its solution. There are two primary dissertation research methods: Qualitative and quantitative.

There are two primary dissertation research methods: Qualitative and quantitative.

1. Qualitative

Qualitative research focuses on examining the topic via cultural phenomena, human behavior, or belief systems. This type of research uses interviews, open-ended questions, or focus groups to gain insight into people’s thoughts and beliefs around certain behaviors and systems.

Ayn O’Reilly, PhD, core research faculty in the School of Public Service Leadership (PSL) and co-chair of the PSL Scientific Merit Review Committee, notes there are several approaches to qualitative inquiry. The three most routinely used include:

Case Study. “This is the most common approach for studying work environments,” says O’Reilly. The research involves the use of multiple sources of data. This might include interviews, field notes, documents, journals, and possibly some quantitative elements (more information on quantitative research follows). A case study focuses on a particular problem or situation faced by a population and studies it from specific angles. For example, a researcher might look at violence in the workplace, focusing on when, where, or how it occurs.

Phenomenology. O’Reilly points to this as the most difficult form of qualitative research, which involves describing a “lived experience” and learning from that experience to help people or organizations that may face that same experience. “The researcher is trying to understand what the experience is like for the subject. For example, take Hurricane Katrina. Whether it’s a NICU [neonatal intensive care] nurse, a member of the National Guard, or a newly homeless widow—the researcher’s job is to assess the full experience of someone involved in large-scale phenomena.” This type of research is difficult partly because of its emotional context. “The researcher needs to know what it is to be that person. It can be very powerful,” says O’Reilly. A researcher using this method will be trained during coursework and residencies in how to conduct this type of research, which involves specialized interviews and surveys with the people involved in the phenomenon.

Generic Qualitative Inquiry. Also called generic qualitative, generic inquiry, or other variations. “This is the fallback approach,” says O’Reilly. “A generic qualitative inquiry is conducted when the student has qualitative research questions, but the study does not meet the requirements of a case study or phenomenology. So the researcher may be using similar methods, but will not have as thorough of a foundation of research available.” For that reason, it’s also less desirable, because the research isn’t going to be as extensive and inclusive. The researcher could run into problems with fewer data to analyze. O’Reilly notes that it’s a better approach for someone who is perhaps seeking a second advanced degree and has done a considerable amount of research, or who just needs to answer a research question or subtopic.

House recommends working on your face-to-face and phone/Skype interview skills if you’re going to use qualitative methods. “You have to understand your own biases and not to ask leading questions. You’ll need to learn when and how to probe more deeply.”

2. Quantitative

Quantitative research involves the empirical investigation of observable and measurable variables. It is used for theory testing, prediction of outcomes, and determining relationships between and among variables using statistical analysis. Ellen Mink, PhD, core research faculty in the School of Public Service Leadership and co-chair of the PSL Scientific Merit Review Committee, outlines two primary data sources for quantitative research.

Primary Data Collection. In this approach, data are collected by the researcher. Participants are recruited for the study, informed consent is obtained, and quantitative data are obtained either electronically or in person by the researcher. This approach allows the researcher to decide exactly what variables he or she is interested in exploring and how they will be operationalized in the study. Variables are measured using instruments whose psychometric properties (reliability and validity) have been established by other authors. Data are analyzed using statistical techniques to assess the nature of the relationships between and among variables.

Secondary Data Analysis. This approach involves the statistical analysis of data collected by other researchers or organizations. There are a number of publicly available data sets for researchers, often from large-scale, federally funded research projects or data repositories. Secondary data analysis may save time for researchers as participant recruitment and data collection are avoided. It is also a way to access information about vulnerable populations in an ethical manner (as it does not involve direct contact). However, when utilizing this approach, researchers must build their research questions based on the available data.

The choice of whether to use a qualitative or quantitative methodology is based on the nature of the questions being asked, the state of the field, and the feasibility of the approach with the population of interest.

“There are so many variations and possibilities,” House says. “PhD students need to be resourceful and willing to shift their expectations as they learn new research techniques. Researching a doctoral dissertation is an ongoing learning process.”

Capella University offers PhD and professional doctorate degree programs ranging from business to education and health to technology. Learn more about Capella’s doctoral programs.